SQL_TRACE is Boolean parameter and has value TRUE/FALSE , and value for Parameter #1 and #2 can be retrieve by executing below query
SELECT s.sid,
s.serial#
FROM v$session s
WHERE s.osuser = '&ENTER_OS_USER_NAME'
AND s.username = '&ENTER_ORACLE_DB_USER_NAME'

we can enable the trace for current session by executing below command
SQL> ALTER SESSION SET SQL_TRACE=TRUE;
SQL> ALTER SESSION SET SQL_TRACE=FALSE;
Or
SQL> EXECUTE dbms_session.set_sql_trace(TRUE);

SQL> Execute SQL statements
SQL> EXECUTE dbms_session.set_sql_trace(FALSE);
Sql Trace always generate raw trace file and it is not very user friendly especially if you are first timers , we can use TKPROF utility to formats a raw SQL Trace file into a user-friendly file. TKPROF reads the Trace file and creates a file that has the following section: